Bark-mill



(No Model.)

1). 'OBRIEN.

Bark M111.

No. 234,324. Patented Nov. 9,1880, WK

lITNESSES: A Ac INVENTOR: /7zC/QmZ 0 6 Q 516 V BY TTORNEYS.

UNITED STATES PATENT OFFICE.

DENNIS OBRIEN, OF OSWAYO, PENNSYLVANIA.

BARK-MILL.

SPECIFICATION forming part of Letters Patent No. 234,324, dated November 9,1880.

Application filed August 13, 1880. (No model.)

To all whom it may concern:

Be it known that I, DENNIS OBRIEN, of Oswayo, in the county of Potter and State of Pennsylvania, have invented anew and useful Improvement in Bark-Mills, of which the following is a specification.

The invention consists in combining a radially-slotted stationary plate provided with grinding-teeth on one edge of each slot with a wheel having teeth on the under side, as hereinafter described.

In the accompanying drawings, Figure l is a central vertical sectional view of a mill em bodying my improvements. Fig. 2 is a horizontal section. Fig. 3 is a detail view. Fig. 4 is a section taken in the line 3 y of Fig. 2.

Similar letters of reference indicate corresponding parts.

A represents a cylindrical casing or chamber, which incloses the working parts. B is avertical shaft, having its lower end stepped in the bottom of the casing and its upper portion journaled in a bar, (3, extending diametrically across the casing and having its ends secured to the sides thereof. The edges of this bar 0 (see Fig. 3) are provided with teeth 0, for the purpose hereinafter described.

D represents a wheel consisting of arms having grinding-teeth on their lower surfaces, and also on their ends. The portion of the casing A immediately surrounding this wheel is provided with grinding-teeth forengagement with the teeth on the ends of the arms of the wheel. The upper portion of each arm is cut out, so as to form a box-like cutting or breaking device having a bottom and two sides, one of the sides being radial and the other parallel with the outer end of the ,arm. The wheel thus formed is attached to the shaft B, and turns with it.

Immediately under the wheel D is a circular plate, F, through the center of which the shaft B passes. This plate is secured to the sides of the casing, so as to remain stationary. It is provided with radial slots f, of a width somewhat less than that of the arms of the wheel, and of sufficient size to screen the bark it discharges.

Each slot has grinding-teeth formed on one edge. The plate is also provided with grinding-teeth on both its upper and lower surfaces, those on the upper surface being for engagement with those on the under surfaces of the arms of the wheel.

The bark to be broken and ground is thrown into the casing or chamber A as the shaft B revolves. The larger pieces of bark are caught between the toothed bar (1 and the upper portions of the arms of the wheel D and broken into smaller pieces, which then pass between the arms and are ground by the action of the teeth of said arms and those on the casing and on the slotted plate F, after which they pass through the slots f to be passed out of the machine.

Gr represents a slotted circular plate attached to the shaft B by means of set-screws g engaging with grooves it, so that said plate may revolve with said shaft and yet be free to rise and fall thereon, said shaft passing through the center of said plate.

J represents a bar, one end of which is pivoted inside of the casing A, and the other end passes out through a slot in said casing, and is connected by a rod, t, with a lever, K, out side of the casing.

The upper surface of the plate G is provided with teeth for engagement with those on the under side of the stationary slotted plate F, both of said series of teeth being finer than those on the upper surface of the plate F.

When the bark has passed through the slotted plate F, as before described, it it is then found to be fine enough, it is allowed to pass through the slots of the revolving plate G and over its rim, the casing being widened for the purpose, and drop to an inclined plane, L, from whence it passes out of the casing through an opening, at.

If it is desired to grind it still finer, the lever K is raised, so as to elevate the bar J and lift the revolving plate G, so that its teeth will engage with those on the under surface of the stationary plate F, after which it passes through the slots of plate G to the inclined plane, as before described.

Having thus fully described my invention, I claim as new and desire to secure by Letters Patent-- 111 bark-mills, the stationary plate provided with radial slots f, having grinding-teeth on one edge of each slot, in combination with the wheel I), having grinding-teeth on its under surface, as shown and described, for the purpose specified.

DENNIS OBRIEN.

Witnesses E. DELAMATER, HUGH D. MELLEN. 

